1. Field of the Invention
The present invention relates generally to systems and processes for digital generation, placement, animation and display of surface-attached geometric objects on computer generated models. More particularly, the present invention relates to the digital generation, placement, animation and display of realistic feathers on animal models.
2. Description of Related Art
Media productions have benefited in recent years from technical advances in animation and in computer generated images. Increasingly, producers and directors of media productions are creating scenes comprising a combination of real and computer generated images that appear to be interacting with each other and co-existing within the same real or virtual space. These new techniques can create realistic special effects such as computer generated dinosaurs, mice or birds interacting with real people, or the destruction of recognizable cities by computer generated asteroids.
These new techniques are used in media productions such as motion pictures, television shows, television commercials, videos, multimedia CD-ROMs, web productions for the Internet/intranet, and the like. One of the many challenges in modeling, animating and rendering believable birds in computer graphics has been to produce realistic-looking feathers. A real feather coat is made up of many individual feathers covering the skin, and fulfills vital functions such as lifting the bird in flight, attracting mates, and protection against cold, moisture and predators. Between different birds, as well as across the body of individual birds, the look and structure of these feathers vary greatly with respect to length, thickness, shape, color, orientation and under/overcoat composition. In addition, feathers are not static, but move and break up as a result of the motion of the underlying skin and muscles, and also due to external influences, such as wind and moisture.
Thus, computer generation of a convincing feather coat which covers the skin of a bird requires dedicated solutions to a number of problems. For instance, it is not feasible to individually model and animate all of the feathers. In addition, interpenetration (“collisions”) may arise, both between neighboring computer generated feathers and between computer generated feathers and the underlying skin surfaces. Also, prior methods of computer generation of feathers do not account for the fact that wet feathers clump together, resulting in a significantly different appearance compared to dry feathers. Furthermore, prior methods of computer generation of feathers do not adequately simulate the effects of wind on a feather coat.
Thus, there is an industry demand for a practical, flexible, robust, efficient and easy to use system and method that can generate realistic computer generated feathers. In addition, there is an industry demand for a system and method that can generate, place and display a large variety of feathers on a bird's skin to create a dense feather coat, while at the same time minimizing interpenetration between computer generated feathers. Furthermore, there is an industry demand for a system and method that can realistically reproduce the effects of moisture and wind on feathers.